Two-piece squeeze plate in a sand moulding machine

ABSTRACT

A molding machine in which a pressure plate and a support plate for a mold box are movable toward each other for compacting molding sand in a mold box placed upon the support plate comprises a pressure plate composed of two complementary parts. These plate parts can be selectively moved either into an engaged position in which they form a continuous pressure plate or into a spaced-apart position. In the latter position the two plate parts open a discharge for feeding molding sand into the box through a feed duct in a housing part of the machine.

United States Patent Inventor 010! John Gerhard Hedberg llalmstad,Sweden Appl, No. 769,594 Filed Oct. 22, 1968 Patented June 29, 1971Assignee Mllcus lndustri Alttiebolag, llalmstad, Sweden Priority Oct.30, 1967 Sweden 1 TWO-PIECE SQUEEZE PLATE IN A SAND MOULDING MACHINE 7Claims, 11 Drawing Figs.

[1.5. CI 164/207, 100/229, 25/103, 164/37 Int. Cl. B22c 15/02 Field ofSearch 164/37, 40, 207, 212; 18/16 C, 16 11,22,18 F; 100/229; 25/103Primary Examiner-J. Spencer Overholser Assistant Examiner-R. SpencerAnnear I Attorney-Bane & Baxley ABSTRACT: A molding machine in which apressure plate and a support plate for a mold box are movable towardeach other for compacting molding sand in a mold box placed upon thesupport plate comprises a pressure plate composed of two complementaryparts. These plate parts can be selectively moved either into an engagedposition in which they fonn a continuous pressure plate or into aspaced-apart position. In the latter position the two plate parts open adischarge for feeding molding sand into the box through a feed duct in ahousing part of the machine.

PATENTEU JUN29 I97; 3. 589 .433

I sum 1 0r 5 INVHNTOR OLOF JOHAN BERNARD HEDBERG 6 Y 71 (dun I4 7ATTOHNIIYG PATENTEDJUNPQIQYI 3,589,433

SHEET u UF 5 INVENTOR OLOF JOHAN GERHARD HEDBIJRG PAIENIEQJuuesm:3.589.433

SHEET 5 OF 5 3f ZNVENTOR OLOF JOHAN GERHARD HIIDBERG 6 '7 WWW 644ATTORNEYS TWO-PIECE SQUEEZE PLATE IN A SAND MOULDING MACHINE The presentinvention relates to sand-molding machines for foundries, andparticularly to a two-piece squeeze plate in a molding machine.

Common to known molding machines is that they contain two horizontaltables or plates which are vertically opposite each other in the workingposition, between which a mold is prepared. The lower plate is thenconnected to a pneumatic lifting and jolting device and constitutes thebase on which the pattern for the mold is set up, as well as a patternframe or molding box, into which the molding material, usually sand, isfilled. In the final molding stage, the mold and sand is pressed betweensaid lower plate, which is raised from its original position andsubjected to jolting, and the upper plate, the squeeze plate, whichthus-functions as a counterholder during the final molding phase. Whenfilling sand into the mold for the molding operation, which fillingtakes place by sand being allowed to fall freely from a sand containerabove the machine to a socalled sand beater and thereafter substantiallyvertically is fed into the mold, the squeeze plate must be moved awaylaterally in order to allow the sand to pass. In known machines, thissqueeze plate is made in the form of one coherentunit, usually having aconsiderable weight, which with its supporting devices takes up a largeportion of the totalweight of the machine and the power consumption. Atthe high production tempo at which mechanized foundries work, the timeavailable for the various molding stages is necessarily very short.Under such circumstances, it will be realized that the time required tomove a coherent, heavy squeeze plate out of the way and back intoposition again can be comparatively long, and can to a high degreeinfluence the total time for the molding procedure. It will moreover berealized that the unsymmetrical movement to be effected by an undivided,heavy squeeze plate out of and back into its working position involvesspecial requirements for the designing of the machine, e.g. as regardsdimensioning, balancing etc. all of which contributes towards anincrease in weight and complexity of the machine.

One purpose of the present invention is to create a squeeze plate for asand-molding machine, which squeeze plate is divided substantially in avertical symmetry plane so that the passage for filling in sand can bearranged by the two halves of the squeeze plate being movedsymmetrically in opposite directions from the dividing plane betweenthem. A considerable saving of time can thereby be made, in that,totally seen, less work is required for the opening and closing of thepassage, compared with the circumstances when an undivided squeeze plateis used, even when it has the same size and weight, as well as aconsiderable saving in weight and dimensioning of the machine, owing tothe more favorable dimensioning requirements which are a result of saidsymmetrical movement.

Another purpose of the invention is to create a squeeze plate intendedfor molding machines, which is divided into two substantiallysymmetrical halves through a dividing plane at right angles to the endsurface and thereby constitutes a new element which provides for thecreation of new solutions within the field of sand-molding machines.

In the following, the present invention will be described in more detailwith reference to the attached drawings, in which FIG. 1 shows inperspective and obliquely from below the main parts of a molding machineprovided with a two-piece squeeze plate according to the invention, thehalves of the squeeze plate being in the process of moving away fromeach other in order to open a sand passage, in which FIG. 2 shows thedesign, in principle, of an embodiment of a squeeze plate according tothe invention and the mounting devices for same, in which I FIG. 3 showsthe main parts of a molding machine with a squeeze plate according tothe invention in a certain working phase, in which FIG. 4 shows the samemolding machine in a working phase following the working phase shown inFIG. 3, in which FIG. 5 shows the same molding machine in the finalphase ofa molding procedure, in which FIG. 6 shows in detail a certaintype of divided squeeze plate and a mold in the same final phase of themolding procedure as in FIG. 5, in which FIG. 7 shows a modified form ofsqueeze plate in the same final phase of the molding procedure, in whichFIG. 8 shows a modified form of squeeze plate together with another typeof mold, in which FIG. 9 shows still another modified form of a dividedsqueeze plate together with still another type of mold, in which FIG. 10shows a molding machine of a conventional kind with a squeeze plateaccording to the invention, and in which FIG. 11 shows another moldingmachine provided with a squeeze plate according to the invention.

FIG. ll shows the two head parts I and 2 of a molding machine betweenwhich the preparation of the mold takes place.

The head part 1 consists of a horizontal pressing table or pressingplate 3, which is fixed to the outer end of the vertically movablepiston rod 4, belonging to a hydraulic or pneumatic joltingand liftingdevice 5. On the pressing plate 3, a pattern'plate 6 with a pattern 6aand a mold 7 are placed in the usual way.

The head part 2, which is located right over the head part 1, consists,according to the present invention, of a horizontal squeeze table orsqueeze plate, which has generally been given the reference designation8 and which is vertically opposite the pressing plate 3 and the moldplaced on same. The squeeze plate 8 consists of two symmetricallyidentical parts and 8b, which are supported so that they aredisplaceable horizontally in a housing 9. The parts 8a and 8b, accordingto what is suitable in the individual case, can be compact'or hollow orhave the form of boxes that are open upwards or boxes that are open atsides facing each other.

The halves 8a and 8b of the squeeze plates can be supported in thehousing 9 in any suitable way whatsoever. In FIG. 1 and for the rest inthe figures, as well as in this description, an alternative for asupport is used which is such that a horizontal strip 10 is arranged atthe top of each side of the squeeze plate halves that is parallel totheir movement, which strips are supported in horizontal straightgrooves 11 on the insides of the sidewalls in said housing 9, as is alsoshown in FIG. 2.

From FIG. 2 it will moreover be noted that the halves 8a and 8b of thesqueeze plate are each provided with fastening members 12a and 12b forthe ends of piston rods 13a and 13b, respectively, of hydraulic orpneumatic pump cylinders 14a and 14b, respectively, the cylinder ends ofwhich are fastened in holders 15a, and 15b, respectively, on the insidesof the end walls of the housing 9.

FIG. 2 also shows how a so-called sand beater, generally designated I6,can be arranged in the housing 9 immediately above the squeeze plate 8and how the housing 9 is arranged to constitute an intake 17 for sand 18which is fed to the sand intake 17 in any conventional way whatsoever.

The functioning of the molding machine comprising the two head parts 1and 2 and particularly the functioning of the head part 2, comprisingthe present invention, will now be described primarily in conjunctionwith FIGS. 3, 4 and 5. In FIG. 3, an empty mold 7 and possibly a newpattern plate 6 have been placed on the pressing plate 3, which has beenraised part of the way towards the squeeze plate 8 ma position suitablefor filling in sand. The halves 8a and 8b are on their way to open up apassage for sand, in that the hydraulic or pneumatic cylinders 14a and14b pull them on their supports 10, I] to an outer position each in thehousing 9.

In FIG. 4, the halves 8a and 8b of the squeeze plate have reached theirouter positions. Sand 18 is being fed from a sand scale 19 to the sandintake 17, being finely distributed while passing the sand beater l6,and is thereafter fed via the open sand passage between the halves 8aand 8b of the squeeze plate to the mold 7. The mold 7 and the patternplate 6 are then subjected to a jolting movement generated by thehydraulic or pneumatic jolting and lifting device 5.

When the feed of a weighed quantity of sand has ceased, the halves 8aand 8b of the squeeze plate are returned by the cylinders 14a and 14b,respectively, to their inner positions, which connect them to eachother, as shown in FIG. 2, and the mold 7 is raised, during continuedjolting, in that a pressure medium is fed to the jolting and liftingdevice 5, so that the sand will be pressed between the squeeze plate 8,i.e. the halves 8a and 8b of the squeeze plate, on one side, and thepattern plate 6 and the mold 7 on the pressing plate 3 on the otherside.

FIG. shows the final phase of the molding procedure, when the fullpressing force has been attained and the sand has been made to tightlyfill up the space in the mold above the pattern plate, the quantity ofsand then, as the case preferably should be, having been adapted so thatthe squeeze plate 8 is inserted into the mold 7 to a minor extent.

Alternatively, the quantity of sand can be adapted so that, at the finalphase of the molding, the mold 7 is pressed between a squeeze platewhich in such a case has a larger pressing surface then the inner crosssection area of a mold, and the pattern plate 6 on the pressing plate 3,as shown in FIG. 6.

An intermediate form 21 of the squeeze plates 8 and 20 according toFIGS. 5 and 6, respectively, is shown in FIG. 7, which has a total crosssection area which is larger than the inner cross section area of themold, but a pressing surface which is somewhat smaller than or equal tothe inner cross section area of the mold, and which extends from ashoulder 21a around the squeeze plate 20. This design of a squeeze plateis used particularly for so-called turning machines, when the mold restson said shoulder of the squeeze plate during one working phase.

Particularly for large molds, reinforcement of the sand in the mold isrequired, which reinforcement can consist of transversal ribs 25, fixedin the upper part of the mold 24 to two opposite walls of the mold, orofa network of crossed ribs 28, 29, which joins all four walls of themold 30 at their upper parts. FIG. 8 shows a squeeze plate 22 which isarranged with ribs 23 at its bottom, which can be inserted into the mold24 between its reinforcing ribs 25. FIG. 9 again shows a squeeze plate26 made with vertical bars or frames 27, arranged in a regular patternof squares on the pressing surface, which frames fit and can be insertedbetween the crossed ribs 28, 29 in the mold 30.

In the foregoing, a clear and explicit description has been given of theprinciple of the design and the embodiment, as well as the functioningofa two-piece squeeze plate according to the invention as one of the twohead parts of a sand molding machine. In FIG. 10, an illustration ofsuch a molding machine 31, ofa substantially conventional type, isgiven. This molding machine, in addition to the actual moldingprocedure, is intended to execute a turning of the mold, and consistsofa turningframe 32, in which a molding frame 33 in the form of atwo-pronged fork is rotatably supported on a horizontal axle 34, whichaxle forms the handle of said two-pronged fork. In one prong 35, a headpart 1 with a lifting and jolting device 5 and a squeeze plate 3 ismounted, and in the other there is a head part 2 with a two-piecesqueeze plate 8 according to the invention in a housing 9. The headparts 1 and 2 together function in identically the same way as has beenpreviously described.

In FIG. 11 still another molding machine is shown, as an example of theuse ofa two-piece squeeze plate according to the present invention. Alsoin this case it is a question of a socalled turning machine, but now notone of a conventional type but a particularly advantageous machine ofanew design, which has become possible only through the creation ofatwopiece squeeze plate according to the present invention. As is clearlyshown in the figure, this machine consists of two parallel, circularturning discs, 37 38 which can be turned on rollers 39 in a machineframe 4 The discs are fixed together by means of an arrangement 41 witha lifting and jolting device near the periphery of the discs at thebottom of the figure, as well as diametrically opposite thelast-mentioned part with an arrangement 42 with a two-piece squeezeplate according to the invention. As regards the molding procedure, andfunctioning of the new machine is identical to that of the one describedabove from the two head parts with a squeeze plate and a pressing plate.

Iclaim:

1. In a molding machine of the kind comprising a pressure plate and asupport plate disposed in parallel relationship and movable toward eachother for compacting loose molding material in a mold box placed betweenthe two plates, the improvement comprising a pressure plate composed oftwo complementary parts selectively displaceable into an engagedposition in which the two plate parts form a continuous pressure plateor into a position in which the two parts are spaced apart to definetherebetween a passage for feeding molding material into the mold boxplaced between the two plates.

2. The molding machine according to claim 1 and further comprising ahousing including a feed duct having an outlet for passage of moldingmaterial through the housing, said parts of the pressure plate beingdisplaceably mounted in said housing so as to close the outlet of saidfeed duct when the plate parts are in the engaged position and to opensaid outlet when the plate parts are in the spaced apart position.

3. The molding machine according to claim 1 wherein said place parts aresubstantially alike and laterally displaceable in the plane of thepressure plate.

4. The molding machine according to claim 1 and comprising a mold boxopen on at least one side, and wherein the peripheral outline of theplate parts in the engaged position thereof overlies the rim on the openside of the mold box.

5. The molding machine according to claim 1 and comprising a mold boxopen on at least one side, and wherein said plate parts are set off onthe side of the pressure plate facing the support plate, the setoffportions of the plate parts having a combined peripheral outlinefittable into the open side of the mold box.

6. The molding machine according to claim 1 and comprising a mold box,the walls of said box and the side of the pressure plate facing thesupport plate having parallel mutually engageable ribs and grooves.

7. The molding machine according to claim 6 wherein said mold box wallsand the pressure plate have additional parallel mutually engageable ribsand grooves crossing said aforementioned ribs and grooves.

1. In a molding machine of the kind comprising a pressure plate and asupport plate disposed in parallel relationship and movable toward eachother for compacting loose molding material in a mold box placed betweenthe two plates, the improvement comprising a pressure plate composed oftwo complementary parts selectively displaceable into an engagedposition in which the two plate parts form a continuous pressure plateor into a position in which the two parts are spaced apart to definetherebetween a passage for feeding molding material into the mold boxplaced between the two plates.
 2. The molding machine according to claim1 and further comprising a housing including a feed duct having anoutlet for passage of molding material through the housing, said partsof the pressure plate being displaceably mounted in said housing so asto close the outlet of said feed duct when the plate parts are in theengaged position and to open said outlet when the plate parts are in thespaced apart position.
 3. The molding machine according to claim 1wherein said place parts are substantially alike and laterallydisplaceable in the plane of the pressure plate.
 4. The molding machineaccording to claim 1 and comprising a mold box open on at least oneside, and wherein the peripheral outline of the plate parts in theengaged position thereof overlies the rim on the open side of the moldbox.
 5. The molding machine according to claim 1 and comprising a moldbox open on at least one side, and wherein said plate parts are set offon the side of the pressure plate facing the support plate, the setoffportions of the plate parts having a combined peripheral outlinefittable into the open side of the mold box.
 6. The molding machineaccording to claim 1 and comprising a mold box, the walLs of said boxand the side of the pressure plate facing the support plate havingparallel mutually engageable ribs and grooves.
 7. The molding machineaccording to claim 6 wherein said mold box walls and the pressure platehave additional parallel mutually engageable ribs and grooves crossingsaid aforementioned ribs and grooves.